title: Test-retest reliability of low-level evoked distortion product otoacoustic emissions.
abstract: OBJECTIVE
  The purpose of this study was to examine test-retest reliability of low-level evoked distortion product otoacoustic emissions (DPOAEs) as a function of L(1), L(2) level; f(2) frequency; and test condition. A predictive relationship between these variables and the presence/absence of DPOAE responses was also examined.
  
  
  METHODS
  Sixteen normal-hearing young adults participated. DPOAEs were evoked to 12 tones with f(2) frequencies ranging from 1500 Hz to 7546 Hz at 4 L(2) levels between 45 dB SPL and 30 dB SPL. Four test conditions were employed: (a) initial test, (b) retest without probe removal, (c) retest with probe reinsertion, and (d) retest with probe reinsertion by a second tester.
  
  
  RESULTS
  L(1), L(2) level and f(2) frequency were statistically significant (p < .0001) predictors of a DPOAE response (i.e., the presence of a DPOAE response was more likely to be observed at higher L(1), L(2) levels and lower f(2) frequencies regardless of test condition). DPOAE levels were significantly affected by L(1), L(2) level and f(2) frequency (p < .0001) but not by test condition. Intra- and intertester test-retest differences were not significantly different.
  
  
  CONCLUSIONS
  The prevalence of missing responses coupled with large intersubject variability and intrasubject test-retest variability are a detriment to the clinical utility of DPOAEs evoked with low-level stimuli.
authors.affiliation: Department of Communication Sciences and Disorders, College of Allied Health Sciences, Health Sciences Building, East Carolina University, Greenville, NC 27858-4353, USA. stuarta@ecu.edu
authors.forename: Andrew
authors.initials: A
authors.lastname: Stuart
authors.forename: Amy L
authors.initials: AL
authors.lastname: Passmore
authors.forename: Deborah S
authors.initials: DS
authors.lastname: Culbertson
authors.forename: Sherri M
authors.initials: SM
authors.lastname: Jones
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D003939:Diagnostic Techniques, Otological; D005260:Female; D018072:Hair Cells, Auditory, Outer / Q000502:physiology*; D006309:Hearing; D006801:Humans; D015203:Reproducibility of Results; D055815:Young Adult